This is a revised proposal for the Psychosocial Core of the HIV Center. Sexual behavior is of central importance in psychosocial research on HIV and AIDS. Since HIV/AIDS is primarily a sexually transmitted disease, sexual risk behavior is the target of most primary and secondary prevention efforts and related research. In addition, research on behavior is the target of most primary and secondary prevention efforts and related research. In addition, research on the quality of life in persons with HIV/AIDS includes sexual functioning as an important issue, because it may be impaired by HIV disease. Various aspects of sexual behavior, its determinants, nd its modification will, therefore, be the focus of both assessment and intervention protocols in the majority of projects within the proposed HIV Center. To meet these needs, the Psychosexual Core has developed a variety of project-tailored sexual risk behavior assessment schedules (SERBAS) and will continue to assist the projects of HIV Center III in the development and modification of individually-tailored SERBAS schedules. Because of the topic's sensitive nature, the assessment of sexual behavior poses a special challenge for interviewers. To improve interviewer performance, and thereby facilitate interviewee self- disclosure and enhance data quality, the Core has developed systematic manualized training procedures for sexual interviewing. The Core will utilize these procedures to train and monitor staff who conduct interviews on sexual behavior ("sex interviewers") throughout the Center. We propose to complement these training procedures by developing training videos, which will also permit easier dissemination of our interviewing nd training procedures. In addition, the Core will conduct sex-assessment workshops that will be open to investigators both inside and outside the Center. To improve efficiency and selection of suitable staff, the Core will develop systematic methods for sex-interviewer selection. Another responsibility of the Core is the analysis of certain sexual-behavior data sets. Because sexual data from complex, behaviorally-oriented interviews pose special analytic problems, the Core will also provide sexual-data- specific consultations on data processing and analysis, which will complement the more broad-band consultations of the SED Core. Finally, the Psychosexual Core serves as an information resource on sex research for the HIV Center, and also participates in the development of new projects. In this context, the Core will provide a sexological forum for Center investigators and others, in the form of regular meetings such as the Psychosexual Conference and the Fellows's Sexuality Seminar, and as a series of special HIV/AIDS-related sexological Lecture/Workshop events.